Filtry
wszystkich: 288
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Wyniki wyszukiwania dla: MULTILEVEL CONFIRMATORY FACTOR ANALYSIS
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Storage of High-Strength Steel Flux-Cored Welding Wires in Urbanized Areas
PublikacjaThe condition of the consumables is a key factor determining the waste reduction in the welding processes and the quality of the welded joint. The paper presents the results of tests of four types of fux-cored wires dedicated for welding high-strength steels, stored for 1 month and 6 months in Poland in two urbanized areas: in a large seaside city (Gdańsk) and in Warsaw, located in the center of the country. The wires were subjected...
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Combination of homogeneous liquid–liquid extraction and vortex assisted dispersive liquid–liquid microextraction for the extraction and analysis of ochratoxin A in dried fruit samples: Central composite design optimization
PublikacjaThis paper presents a new analytical procedure based on combination of homogeneous liquid–liquid extraction (HLLE) and vortex-assisted dispersive liquid–liquid microextraction (VA-DLLME) for the accurate and reliable determination of ochratoxin A (OTA) in dried fruit samples. To enable selective extraction of the OTA, six hydrophobic deep eutectic solvents (hDESs) were prepared and tested as extraction solvents. Optimization of...
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Investigation of use of hydrophilic/hydrophobic NADESs for selective extraction of As(III) and Sb(III) ions in vegetable samples: Air assisted liquid phase microextraction and chemometric optimization
PublikacjaIn this paper, a green, cost-effective sample preparation method based on air assisted liquid phase microextraction (AA-LPME) was developed for the simultaneous extraction of As(III) and Sb(III) ions from vegetable samples using hydrophilic/hydrophobic natural deep eutectic solvents (NADESs). Central composite design was used for the optimization of extraction factors including NADES volume, extraction cycle, pH, and curcumin concentration....
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Prediction of Overall In Vitro Microsomal Stability of Drug Candidates Based on Molecular Modeling and Support Vector Machines. Case Study of Novel Arylpiperazines Derivatives
PublikacjaOther than efficacy of interaction with the molecular target, metabolic stability is the primary factor responsible for the failure or success of a compound in the drug development pipeline. The ideal drug candidate should be stable enough to reach its therapeutic site of action. Despite many recent excellent achievements in the field of computational methods supporting drug metabolism studies, a well-recognized procedure to model...
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Knowledge Safety in Small and Medium Sized Service Companies:Case Study Analysis
PublikacjaPurpose: This paper aims to explore the topic of knowledge safety, defined as the state of knowledge being safe from loss, attrition, oblivion or theft. The paper first presents a theoretical background and review of previous studies on knowledge loss and retention and then illustrates the topic of knowledge safety with ten case studies from the small and medium-sized enterprises (SMEs) sector. Methodology: The paper is based...
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Knowledge Safety – Insights from the SME Sector
PublikacjaPurpose: This paper aims to explore the topic of knowledge safety, defined as the state of knowledge being safe from loss, leakage, attrition, oblivion, waste or theft. The paper first presents a theoretical background and review of previous studies on knowledge loss and ways of overcoming it, and then illustrates the topic of knowledge safety with ten case studies from the small and medium-sized enterprises (SMEs) sector. Methodology:...
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Modeling of Passive and Forced Convection Heat Transfer in Channels with Rib Turbulators
PublikacjaThe main goal of the research presented in this paper was the experimental and numerical analysis of heat enhancement and aerodynamic phenomena during air flow in a channel equipped with flow turbulators in the form of properly configured ribs. The use of ribs intensifies the heat transfer and at the same time increases not only the flow resistance but also the energy costs. Therefore, designing modern heat exchangers with optimal...
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Coupling transformation of carbon, nitrogen and sulfur in a long-term operated full-scale constructed wetland
PublikacjaThe coupling transformation of carbon, nitrogen and sulfur compounds has been studied in lab-scale and pilot-scale constructed wetlands (CWs), but few studies investigated full-scale CW. In this study, we used batch experiments to investigate the potentials of carbon, nitrogen and sulfur transformation in a long-term operated, full-scale horizontal subsurface flow wetland. The sediments collected from the HSFW were incubated for...
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Evaluation of a company’s image on social media using the Net Sentiment Rate
PublikacjaVast amounts of new types of data are constantly being created as a result of dynamic digitization in all areas of our lives. One of the most important and valuable categories for business is data from social networks such as Facebook. Feedback resulting from the sharing of thoughts and emotions, expressed in comments on various products and services, is becoming the key factor on which modern business is based. This feedback is...
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Computer Simulation in Predicting Biochemical Processes and Energy Balance at WWTPs
PublikacjaNowadays, the use of mathematical models and computer simulation allow analysis of many different technological solutions as well as testing various scenarios in a short time and at low financial budget in order to simulate the scenario under typical conditions for the real system and help to find the best solution in design or operation process. The aim of the study was to evaluate different concepts of biochemical processes and...
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Expedite EM-driven generation of Pareto-optimal trade-off curves for variable-turn on-chip inductors
PublikacjaThis work presents a novel approach to computationally efficient Pareto front identification for variable-turn on-chip inductors. The final outcome is a set of solutions that correspond to the best trade-offs between conflicting design objectives. Here, we consider minimising inductor area and, simultaneously, maximising its quality factor, while maintaining a specified inductance value at a given operating frequency. As opposed...
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Modernization and adaptation of historical interiors
PublikacjaModernization of the historical building's interior entails the need to take many decisions, often conflicting. Operational requirements, protection of the architectural heritage, fire-safety recommendations, construction regulations, all these aspects involve a whole set of problems that require a rational solution, respecting ambient architectural and historical value, as well as the needs arising from the planned transformation....
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An Experimental and Numerical Analysis of Water Hammer Phenomenon in Slurries
PublikacjaThe analysis of slurry transportation in pressure pipelines is important both from practical and theoretical point of view. Due to the nature of the medium, the number of problems arising in the course of design, operation, measurements and mathematical modeling is much higher compared to the cases where the flowing liquid is homogeneous. The equations describing the flow are more complex, and higher number of the parameters is...
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Investigating lubricants behaviour in microgravity for vibration damping purposes
PublikacjaVibration is one of the harshest environments an object is exposed to during and after launch into space on a launch vehicle. Such vibrations should be damped to avoid destruction of the spacecraft or its elements. Currently, active and material damping is used. A possibility of using lubrication as the damping factor is suggested by some research. MoS2 is a typical solid lubricant used in space applications. Its properties vary...
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Explicit Size-Reduction of Circularly Polarized Antennas through Constrained Optimization with Penalty Factor Adjustment
PublikacjaModern communication systems of high data capacity incorporate circular polarization (CP) as the preferred antenna radiation field configuration. In many applications, integration of the system circuitry with antennas imposes size limitations on CP radiators, which makes their development process a challenging endeavor. This can be mitigated by means of simulation-driven design, specifically, constrained numerical optimization....
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Short-Term Observations of Rainfall Chemistry Composition in Bellsund (SW Spitsbergen, Svalbard)
PublikacjaGlobal warming results in increasingly widespread wildfires, mostly in Siberia, but also in North America and Europe, which are responsible for the uncontrollable emission of pollutants, also to the High Arctic region. This study examines 11 samples of rainfall collected in August in a coastal area of southern Bellsund (Svalbard, Norway). It covers detailed analysis of major ions (i.e., Cl−, NO3−, and SO42−) and elements (i.e.,...
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Low temperature rotary Stirling engine: conceptual design and theoretical analysis
PublikacjaThe use of low-temperature energy sources for electricity generation demands a dual focus: a substantial enhancement in the efficiency of energy conversion devices and a reduction in system production costs. Particularly in scenarios where low-temperature energy sources are scarce, this factor can be pivotal in facilitating widespread adoption of such technologies. The Stirling engine emerges as a promising solution capable of...
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Wskaźnik przedsiębiorczości w jednostkach terytorialnych Polski – zróżnicowanie w czasie i przestrzeni
PublikacjaPrzedmiotem artykułu jest analiza zjawiska prowadzenia działalności gospodarczej przez osoby fizyczne, mierzonego poprzez wskaźnik liczby tych osób na 100 osób w wieku produkcyjnym. Wskaźnik ten nazywany jest nieraz wskaźnikiem przedsiębiorczości, mimo, że mierzy tylko jeden z jej przejawów. Badania prowadzono w układzie podregionów, powiatów i gmin (według ich rodzaju, z wyodrębnieniem miast w gminach miejsko-wiejskich). Celem...
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MutS3: a MutS homologue of unknown biological function
PublikacjaThe homologues of MutS proteins are widespread among both Prokaryotes and Eukaryotes. MutS designated as MutS1 is a part of MMR (mismatch repair) system which is responsible for removal of mispaired bases and small insertion/deletion loops in DNA. Initially, the only MutS homologues known were those engaged in mismatch repair and these were later designated as MutS1. Subsequently, the MutS2 homologue was distinguished. MutS2 does...
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Evaluation of Pavement Temperatures in Poland During Winter Conditions
PublikacjaThe paper presents the analysis of pavement temperatures from meteorological stations located at the Polish national roads during the impact of low winter temperatures. Presented issue is particularly important in view of the problem of low-temperature cracks that occur in the asphalt pavement under the influence of low temperatures. For each location of meteorological station there were analysed measurements of the temperature...
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Analysis of start energy of Stirling engine type alpha
PublikacjaThe Stirling engine type alpha is composed of two cylinders (expansion space E and compression space C), regenerator that forms the space between the cylinders and the buffer space (under the pistons). Before the start-up and as a result of long-term operation, the average pressure in the working space (above the pistons) and in the buffer space is the same. However, in the initial phase of operation, the average pressure in the...
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Residents’ Perception of Intangible Benefits and Costs Associated with Hosting Major Sporting Events
PublikacjaThe main purpose of this paper is to estimate on the basis of inhabitants’ perception the overall composite and aggregated scores of two major sporting events held in Ergo Arena hall, on the border of Gdańsk and Sopot, in northern Poland. The indirect aim is to identify the determinants affecting the monetary offers of the locals of the two cities. The research results unveil that major sporting events may determine the appearance...
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Flooding Extent Mapping for Synthetic Aperture Radar Time Series Using River Gauge Observations
PublikacjaThe flooding extent area in a river valley is related to river gauge observations such as discharge and water elevations. The higher the water elevations, or discharge, the larger the flooding area. Flooding extent maps are often derived from synthetic aperture radar (SAR) images using thresholding methods. The thresholding methods vary in complexity and number of required parameters. We proposed a simple thresholding method that...
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Rotational Molding of Linear Low-Density Polyethylene Composites Filled with Wheat Bran
PublikacjaApplication of lignocellulosic fillers in the manufacturing of wood polymer composites (WPCs) is a very popular trend of research, however it is still rarely observed in the case of rotational molding. The present study aimed to analyze the impact of wheat bran content (from 2.5 wt.% to 20 wt.%) on the performance of rotationally-molded composites based on a linear low-density polyethylene (LLDPE) matrix. Microscopic structure...
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Social Differentiation of the Perception and Human Tissues Donation for Research Purposes.
PublikacjaThe willingness to donate human biological material for research purposes is shaped by socio-cultural factors; however, there is a lack of studies analysing the social perception of different human tissues, which may affect such willingness. This study aimed to distinguish different sociocultural categories of human tissues and types of potential donors based on their willingness to donate material. Quantitative research was...
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INFLUENCE OF MEASURING CONDITIONS ON TYRE/ROAD NOISE
PublikacjaA decisive factor for the development of tyres and road surfaces is the ability to conduct representative and reproducible measurements of selected characteristics related to the interaction of tyres and road surfaces. In terms of tyre/road noise measurements in Europe two methods described in ISO/FDIS 11819-2 and ECE Regulation No.117 are used. The latter is compulsory for assigning the tyre noise labels. The methodologies differ...
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KM Challenges in Small KIBS Companies: Multi-case Analysis in Two Countries
PublikacjaKnowledge Intensive Business Services (KIBS) – i.e. companies like e.g. computer services, consulting, engineering, business communication, and R&D support - are key players in the modern economies. They stimulate the innovativeness of businesses and societies. Their competitiveness is based on knowledge, which is their key production factor and also the kind of “goods” they sell. The large majority of KIBS companies have a small...
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Intensification of catechin extraction from the bark of Syzygium cumini using ultrasonication: Optimization, characterization, degradation analysis and kinetic studies
PublikacjaCatechin is a prominent polyphenolic component that possesses various medicinal properties. Present work communicates the intensification and optimization of catechin extraction from the bark of Syzygium cumini tree using stirred reactor, soxhlet, ultrasonic bath, and ultrasonic horn technique. The optimization of several parameters such as type of solvent, solid to solvent ratio (1:100 w/v), speed of agitation (300 RPM), extraction...
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Chemically reduced graphene oxide based aerogels - Insight on the surface and textural functionalities dependent on handling the synthesis factors
PublikacjaEfficient adjusting of reduced graphene oxide aerogels properties requires information about experimental factor-aerogel property relationship. In this work, the reduced graphene oxide aerogels surface and textural functionalities in relation to precursor concentration, gelation time and hydrogel freezing temperature were studied in detail, with the use of dynamic adsorption method of gaseous organic probes and experimental design....
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Mineral Composition of Dietary Supplements-Analytical and Chemometric Approach
PublikacjaThere is a lack of data on the actual composition and effectiveness of beetroot-based dietary supplements. The research aimed to determine the profile of 22 elements (Na, K, Ca, Mg, P, Fe, As, Se, Zn, Cu, Ag, Co, Ni, Mo, Al, Mn, Sr, Cr, Ba, Li, Pb, Cd) in beetroot and its supplements by the microwave plasma atomic emission spectrometry (MP-AES) method. The analytical procedure was optimised and validated. The composition of both...
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Residents' Perception of Intangible Benefits and Costs Associated with Hosting Major Sporting Events
PublikacjaThe main purpose of this paper is to estimate on the basis of inhabitants’ perception the overall composite and aggregated scores of two major sporting events held in Ergo Arena hall, on the border of Gdańsk and Sopot, in northern Poland. The indirect aim is to identify the determinants affecting the monetary offers of the locals of the two cities. The research results unveil that major sporting events may determine the appearance...
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Performance of Vector-valued Intensity Measures for Estimating Residual Drift of Steel MRFs with Viscous Dampers
PublikacjaViscous Dampers (VDs) are widely used as passive energy dissipation system for improving seismic performance levels especially in retrofitting of buildings. Residual Inter-story Drift Ratio (R-IDR) is another important factor that specifies the condition of building after earthquake. The values of R-IDR illustrates the possibility of retrofitting and repairing of a building. Therefore, this study aims to explore the vector-valued...
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Optimization of vortex-assisted supramolecular solvent-based liquid liquid microextraction for the determination of mercury in real water and food samples
PublikacjaA novel method was developed for sample preparation for spectrophotometric determination of Hg(II) in water and food samples. The method was based on vortex-assisted supramolecular solvent-assisted liquid-liquid microextraction (VA-SUPRASs-LLME). Analytical parameters such as pH, chelating agent, solvent type and volume, vortex time and salting out effect were optimized. Surface and normal probability plots were drawn for the variables...
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Metoda TrustCritic oceny wiarygodności sklepów internetowych
PublikacjaW artykule przedstawiono metodę oceny wiarygodności sklepów internetowych TrustCritic. Powszechnie występujące nadużycia w handlu elektronicznym sprawiają, że zaufanie do przedsiębiorcy staje się kluczowym czynnikiem decyzji konsumentów. Przedsiębiorca narażony jest na niezgodność z prawem, utratę wizerunku i klientów. Artykuł omawia problematykę nadużyć w sferze e-biznesu oraz proponuje wielokryterialny model oceny sklepu internetowego,...
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The preparation and evaluation of core-shell magnetic dummy-template molecularly imprinted polymers for preliminary recognition of the low-mass polybrominated diphenyl ethers from aqueous solutions
PublikacjaThe design, preparation process, binding abilities, morphological characteristic and prospective field of application of dummy-template magnetic molecularly imprinted polymer (DMMIP) for preliminary recognition of the selected low-mass polybrominated diphenyl ethers (PBDE-47 and PBDE-99) from aquatic environment were investigated. The surface of iron oxide (Fe3O4) nanopowder (50-100 nm particles size) was modified with tetraethoxysilane...
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Kinetics of Cross-Linking Reaction of Epoxy Resin with Hydroxyapatite-Functionalized Layered Double Hydroxides
PublikacjaThe cure kinetics analysis of thermoset polymer composites gives useful information about their properties. In this work, two types of layered double hydroxide (LDH) consisting of Mg2+ and Zn2+ as divalent metal ions and CO32− as an anion intercalating agent were synthesized and functionalized with hydroxyapatite (HA) to make a potential thermal resistant nanocomposite. The curing potential of the synthesized nanoplatelets in the...
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Uncertainty Quantification of Additive Manufacturing Post-Fabrication Tuning of Resonator-Based Microwave Sensors
PublikacjaReconfigurability, especially in terms of the ability of adjusting the operating frequency, has become an important prerequisite in the design of modern microwave components and systems. It is also pertinent to microwave sensors developed for a variety of applications such as characterization of material properties of solids or liquids. This paper discusses uncertainty quantification of additive-manufacturing-based post-fabrication...
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Study of a Multicriterion Decision-Making Approach to the MQL Turning of AISI 304 Steel Using Hybrid Nanocutting Fluid
PublikacjaThe enormous use of cutting fluid in machining leads to an increase in machining costs, along with different health hazards. Cutting fluid can be used efficiently using the MQL (minimum quantity lubrication) method, which aids in improving the machining performance. This paper contains multiple responses, namely, force, surface roughness, and temperature, so there arises a need for a multicriteria optimization technique. Therefore,...
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Facet effect of TiO2 nanostructures from TiOF2 and their photocatalytic activity
PublikacjaIn this study, special attention is focused on the design of TiO2 morphology and microstructure in the two-step preparation procedure using TiOF2 as a precursor to study their photodegradation mineralization efficiency. Firstly, TiOF2 was synthesized by a simple solvothermal method using titanium(IV) tetrafluoride, which was further used as a precursor in preparation of anatase 2D nanosheets, octahedral, decahedral, and rectangular prisms...
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Modeling of medium flow processes in transportation pipelines - the synthesis of their state-space models and the analysis of the mathematical properties of the models for leak detection purposes
PublikacjaThe dissertation concerns the issue of modeling the pipeline flow process under incompressible and isothermal conditions, with a target application to the leak detection and isolation systems. First, an introduction to the model-based process diagnostics is provided, where its basic terminology, tools, and methods are described. In the following chapter, a review of the state of the art in the field of leak detection and isolation...
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UAV Photogrammetry under Poor Lighting Conditions—Accuracy Considerations
PublikacjaThe use of low-level photogrammetry is very broad, and studies in this field are conducted in many aspects. Most research and applications are based on image data acquired during the day, which seems natural and obvious. However, the authors of this paper draw attention to the potential and possible use of UAV photogrammetry during the darker time of the day. The potential of night-time images has not been yet widely recognized,...
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Mechanical Properties of Bio-Composites Based on Epoxy Resin and Nanocellulose Fibres
PublikacjaThe aim of our research was to investigate the effect of a small nanocellulose (NC) addition on an improvement of the mechanical properties of epoxy composites. A procedure of chemical extraction from pressed lignin was used to obtain nanocellulose fibers. The presence of nanoparticles in the cellulose pulp was confirmed by FTIR/ATR spectra as well as measurement of nanocellulose particle size using a Zetasizer analyzer. Epoxy...
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Microbial diversity of inflamed and noninflamed gut biopsy tissues in inflammatory bowel disease.
PublikacjaBACKGROUND: Inflammatory bowel disease (IBD) is a chronic gastrointestinal condition without any known cause or cure. An imbalance in normal gut biota has been identified as an important factor in the inflammatory process. METHODS: Fifty-eight biopsies from Crohn's disease (CD, n = 10), ulcerative colitis (UC, n = 15), and healthy controls (n = 16) were taken from a population-based case-control study. Automated ribosomal intergenic...
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FAILURE OF MAGNETIC FLUID SEALS OPERATING IN WATER: PRELIMINARY CONCLUSIONS
PublikacjaThe article analyses properties of magnetic fluid seals installed in rotary sealing no des which operate in the utility water environment. Seals of this type have been examined as a possible solution to the problem with ship manoeuvring propulsion sealing. The present analysis bases on laboratory durability tests of magnetic fluid seals expo sed to long - term utility water loads, at different water pressures and shaft revolutions....
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Structure and Stability Characterization of Natural Lake Pigments Made from Plant Extracts and Their Potential Application in Polymer Composites for Packaging Materials
PublikacjaNatural dyes were extracted from various plant sources and converted into lake pigments based on aluminum and tin. Three different plants (weld, Persian berries, and Brazilwood) were chosen as representative sources of natural dyes. High-performance liquid chromatography (HPLC) and triple-quadrupole mass spectrometry (QqQ MS) were used to identify dyestuffs in the raw extracts. The natural dyes and lake pigments were further characterized...
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The correlation of fractal dimension to fracture surface slope for fatigue crack initiation analysis under bending-torsion loading in high-strength steels
PublikacjaIn this study, the fractal dimension of fatigue fracture surfaces is investigated in order to find an alternative failure loading indicator. Some of many metrological factors are generalized by reducing the fracture surface structure to one factor and develop an entire fracture surface procedure by analyzing the impact of surface slope and calculation resolution. Three notched geometries are studied under cyclic bending-torsion:...
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Importance of Bile Composition for Diagnosis of Biliary Obstructions
PublikacjaDetermination of the cause of a biliary obstruction is often inconclusive from serum analysis alone without further clinical tests. To this end, serum markers as well as the composition of bile of 74 patients with biliary obstructions were determined to improve the diagnoses. The samples were collected from the patients during an endoscopic retrograde cholangiopancreatography (ERCP). The concentration of eight bile salts, specifically...
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Krytyczne działania i czynniki sukcesu wdrażania projektów informatycznych
PublikacjaCelem niniejszego artykułu jest określenie, jakie działania powinny podjąć organizacje gospodarcze, aby zidentyfikowane krytyczne czynniki sukcesu projektów informatycznych, pozwalające na zwiększenie prawdopodobieństwa pomyślnego zakończenia przedsięwzięcia, zmaterializowały się. Na potrzeby niniejszego artykułu przeprowadzono badania własne. Jako metodę wybrano analizę przypadków. Badanie przeprowadzono w organizacji, która prowadziła...
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Powikłania po rekonstrukcji piersi: problem zakażeń i strategii prewencyjnej - przegląd literaturowy
PublikacjaW niniejszej pracy przedstawiono dane dotyczące powikłań po rekonstrukcji piersi. Manuskrypt ma na celu usystematyzowanie wyników badań z ostatnich lat wraz z aspektami, takimi jak: częstotliwość występowania powikłań oraz ich rodzaj, czynniki predysponujące, a także możliwości profilaktyki. Przeanalizowano dane literaturowe z ogólnie dostępnych artykułów z okresu ostatnich pięciu lat, ze szczególnym uwzględnieniem zakażeń. Do...
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Medieval Bourgeois Tenement Houses as an Archetype for Contemporary Architectural and Construction Solutions: The Example of Historic Downtown Gdańsk
PublikacjaThe basic urban tissue of medieval European cities consisted of brick townhouses. In the cities of northern Europe, these tenements were characterised by a block based on an elongated rectangular plan, covered with a gable roof with a ridge oriented perpendicularly to the street. The side walls of the tenement house were common for both neighbours and constituted a basic structural element. The gable façades were not loaded with...